Charge air pressure sensor -G31-, testing

Special tools, testers and other equipment required 

• V.A.G 1526 A
• V.A.G 1594 A
• V.A.G 1598/31
• VAS 5051 with VAS 5051/1

• or

• V.A.G 1551 with V.A.G 1551/3 A

• Connect vehicle diagnostic, testing and information system VAS 5051 (or DTC reader V.A.G 1551) and select engine electronics control module by entering "Address word" 01. When doing this the engine must be running at idling speed.

Refer to

• 01 ON BOARD DIAGNOSTIC (OBD) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AMU
• 01 ON BOARD DIAGNOSTIC (OBD) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): ATC
• 01 ON BOARD DIAGNOSTIC (OBD) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AWP
• 01 ON BOARD DIAGNOSTIC (OBD) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): BEA

; On Board Diagnostic of Motronic system; Connecting VAS 5051 tester or V.A.G 1551 scan tool and selecting functions

• Interrogate DTC memory of engine control module.

Refer to

• 01 ON BOARD DIAGNOSTIC (OBD) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AMU
• 01 ON BOARD DIAGNOSTIC (OBD) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): ATC
• 01 ON BOARD DIAGNOSTIC (OBD) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AWP
• 01 ON BOARD DIAGNOSTIC (OBD) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): BEA

; Checking and erasing DTC memory

If the display shows a DTC relating to charge air pressure sensor -G31-:

Testing voltage supply 

• Disconnect electrical connector on charge air pressure sensor.

• Connect multimeter (voltage measurement range) between contacts 1 and 3 on connector.
• Switch on ignition.

• Specification: approx. 5 V

If the specification is not attained:

• Connect test box V.A.G 1598/31 to wiring harness for engine control module and also to the engine control module itself (-1-).

Refer to

• 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AMU
• 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): ATC
• 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): AWP
• 24 MULTIPORT FUEL INJECTION (MFI) for 1.8 LITER 4-CYL. 5V TURBO FUEL INJECTION & IGNITION, ENGINE CODE(S): BEA

; Servicing Motronic injection system; Wiring and component test using test box V.A.G 1598/31

• Test for open circuit and short to positive or Ground in the following wiring connections:

Connector  Contact	Test box V.A.G 1598/31  Contact
1	108
3	98

• Rectify short circuit or open circuit if necessary.

If the specification is attained:

Testing signal wire 

• Plug in connector on charge air pressure sensor.
• Connect multimeter (voltage measurement range) between sockets 101 and 108 on test box.
• Start engine and run at idling speed.

• Specification: approx. 1.90 V

• Increase engine speed by operating throttle quickly.

• Specification: 2.00 - 3.00 V

If the specifications are not obtained:

• Test for open circuit and short to positive or Ground in the following wiring connections:

Connector  Contact	Test box V.A.G 1598/31  Contact
4	101

• Rectify short circuit or open circuit if necessary.

If the wiring is OK:

• Replace charge air pressure sensor -G31-.